You don't get what you expected because
%DATE% returns the current date using the windows settings for the "short date format". This setting is fully (endlessly) customizable.
One user may configure its system to show the short date as Fri040811; while another user (even in the same system) may choose 08/04/2011. It's a complete nightmare for a BAT programmer.
One possible solution is to use WMIC, instead. WMIC is the WMI command line interface to WMI. WMI Windows Management Instrumentation is the http://en.wikipedia.org/wiki/Windows_Management_Instrumentation
WMIC Path Win32_LocalTime Get Day,Hour,Minute,Month,Second,Year /Format:table
returns the date in a convenient way to directly parse it with a
Completing the parse and putting the pieces together
FOR /F "skip=1 tokens=1-6" %%A IN ('WMIC Path Win32_LocalTime Get Day^,Hour^,Minute^,Month^,Second^,Year /Format:table') DO (
SET /A TODAY=%%F*10000+%%D*100+%%A